php实现图书管理系统的增删改查

以下是使用PHP实现图书管理系统的增删改查的示例代码：

1. 添加图书：

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 获取表单数据
$bookName = $_POST['bookName'];
$author = $_POST['author'];
$price = $_POST['price'];

// 插入数据
$sql = "INSERT INTO books (bookName, author, price) VALUES ('$bookName', '$author', '$price')";
mysqli_query($conn, $sql);

// 关闭数据库连接
mysqli_close($conn);
?>

2. 删除图书：

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 获取要删除的图书ID
$bookId = $_GET['bookId'];

// 删除数据
$sql = "DELETE FROM books WHERE bookId = $bookId";
mysqli_query($conn, $sql);

// 关闭数据库连接
mysqli_close($conn);
?>

3. 修改图书：

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 获取表单数据
$bookId = $_POST['bookId'];
$bookName = $_POST['bookName'];
$author = $_POST['author'];
$price = $_POST['price'];

// 更新数据
$sql = "UPDATE books SET bookName = '$bookName', author = '$author', price = '$price' WHERE bookId = $bookId";
mysqli_query($conn, $sql);

// 关闭数据库连接
mysqli_close($conn);
?>

4. 查询图书：

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 查询数据
$sql = "SELECT * FROM books";
$result = mysqli_query($conn, $sql);

// 输出查询结果
while ($row = mysqli_fetch_assoc($result)) {
    echo "书名：" . $row['bookName'] . "<br>";
    echo "作者：" . $row['author'] . "<br>";
    echo "价格：" . $row['price'] . "<br><br>";
}

// 关闭数据库连接
mysqli_close($conn);
?>